Electrohydraulic operator



March 9, 1954 N. E. HEINTZELMAN ELECTROHYDRAULIC OPERATOR 2 Sheets-Sheetl Filed Dec. 19, 1949 N m T L M E V /N W 0b E H. :L 5 mi: /M ,u WW x M MA Z s a Z l `.e A/ r l. mmmmmm 4 ws 3 1 z o s u n s d ET-:SI5 u z G nArran/er March 9, 1954 N. E. HEINTZELMAN 2,671,317

ELECTROHYDRAULIC OPERATOR AT1-aznar Patented Mar. 9, 1954ELECTROHYDRAULIC OPERATOR Norton E. Heintzelman, Grand Rapids, Mich.,as-

signor to Wolverine Finishes Corporation, Grand Rapids, Mich., acorporation of Michigan Application December 19, 1949, Serial No.133,741

4 Claims. l

The present invention provides a remotelycontrollable actuatorparticularly Well adapted for use with valve mechanisms. Motor-operatedvalves are not broadly new, but the particular characteristics of thepresent invention open a much broader field of utility for this type ofdevice. In situations where many storage tanks and associated conduitsystems become involved in carefully controlled mixing and processingoperations, it is highly desirable to make use of a large number ofhighly reliable valve mechanisms which can be controlled from a centralpoint. It is obvious that if a valve is not to be periodically attendedby a worker in order to open and close the same, the mechanism must beof the utmost reliability in view of the absence of the cursoryinspection that is automatically made each time a valve is manuallyoperated. It is also necessary that the extremes of open and closedpositions must be positive and that leakage must be absolutelyprevented. This latter is not only necessary to preserve the quality ofthe mixing operations, but to protect the valve itself from the effectsof erosion clue to the passage of minute quantities of fluid over thevalve surfaces under pressure as is the case when the valve surfaces donot positively seat tightly.

Users of this type of equipment have found it also to be desirable thata valve shall have a normal position either completely open orcompletely closed, with that position being determined by the mechanismitself and not by outside control equipment. The value of thisarrangement is obvious if it be considered for a moment that a powerfailure might occur before a valve shall have reached a nal position.The continuous passage of the fluid through a partially opened valvewould not only disturb the mixing or metering operations but wouldendanger the contours of the valve surfaces as outlined above. It hasbeen found most valuablethat the normal position of a valve should befully closed, so that the seating of the valve shall be determined byforces that are constant and not dependent upon outside influences.` Thepower mechanism is therefore utilized to open the valve and to hold itin the opened position as long as is desired.

Another problem in the design of power-operated valve mechanisms hasbeen the tendency for the controlled fluid to find its way betweenrelatively moving surfaces and either generate corrosion of themechanical parts or remove the lubricant so`as to permit `undue Wear.Where hydraulic valve, mechanisms areused, an added 2 problem occurs dueto the tendency of the controlled fluid to become mixed with and alterthe characteristics of the hydraulic fluid. ,L

As a practical matter, the size and relative cost of a valve mechanismis of extreme importance; for if the performance characteristics weretoA completely solve all of the problems involved, it would still benecessary that the cost of installing the devices would not render theproject prohibitive. As these mechanisms are frequently used inconnection with large numbers of conduits associated with a relativelysmall room or shelter, it is obvious that their overall dimensions mustbe a minimum to permit their installation in banks in which they are asclosely spaced asfthe requirements of the various conduits mightrequire.

A large amount of the utility of this type of mechanism is associatedwith its adaptability for use with a central control station, and it isobvious that the amount of energy necessary to operate the valve shouldbe reduced to a minimum to avoid undue complexity of the control stationand also to minimize the cost of the system communicating between thecontrol station and the valve mechanism. All this must be accomplishedwhile retaining a relatively large actuating force necessary to operatevalves in which a, considerable amount of pressure is required betweenthe valve surfaces, as in the case of liquids having an extremely lowviscosity and a tendency to leak through even the closest fittingsurfaces.

The present invention provides a valve mechanism which will satisfy theabove requirements. The force-applying system is built around ahydraulic actuating mechanism operated by a pump driven by an electricmotor, in the preferred form of the invention. The piston rod associatedwith the hydraulic actuator is continued to form a force-applying memberdirectly associated with the moving valve surface. To create a normallyclosed position of the mechanism, a heavy coinpression spring is placedin position to continually urge the valve in the desired direction. Theopening of the valve involves the running of the motor to cause the pumpto generate suicient pressure to oppose the spring and to raise thevalve from its seat. If the motor is stopped, the pressure is removedfrom the piston, and the valve is again moved into the closed positionby the action of the spring. Obviously, this type of arrangementrequires a by-pass permitting the egress of the hydraulic fluid when thepressureis not desired. This by-pass can be of either such smalldimensions that the continued flow through it is small in comparisonwith the delivery of the pump, or the by-pass may be valve-controlled sothat it is open only during the period in which the pump is not active.The preferred and simplest form of the invention, however, involves theuse of a screw rotating at high speed within the hydraulic fluid andclosely .surrounded by a suitable chamber. The inter-action between thefixed walls of the chamber and the rotating screw causes a tendency forthe hydraulic fluid to be moved axially lalong the chamber and togenerate the required pressure. When the rotation of the screw stops, ahelical path around the threads forms the required by-pass mentionedabove, and auxiliary conduits are not necessary.

Mechanism is provided for the holding valve in the open position. Thismechanism is of the active type in which maintenance of energy supply isnecessary to maintain the holding device' in holding position. Theabsence of this energy supply permits the holding device to becomeinoperative and again permits the valve to be moved to closed positionunder the action of the spring. The most easily controlled form ofholding mechanism has been found to include a pivoted plate having aprojection which engages a suitable recess in a member directlyassociated with the force-applying rod as soon as the rod reaches theopen position. When this condition exists, the holding plate comes intoengagement with a, suitable magnetic neld and is securely heldin thatposition by the effects of a small amount of electrical current suppliedto the coil generating the field. The termination of running of themotor suiciently to raise the valve to the opened position, and thesubsequent holding of that position, it follows that the running of themotor may be terminated as soonas the opened position has been reached'.This is provided for by the present invention by the use of a switchoperated upon by the holding member. As soon as the holding memberreaches cooperating position with the magnetic field, a projection comesto bear upon a switch which terminates they running of` the motor. Thesupply roi.' energy to the device after this point has been reached issolely that which is required to maintain the magnetic field.

In order to isolate the hydraulic fluid and the moving parts of themechanism from the controlled fluid, a bellows-type connection surroundsthe actuating rod and the opening through which the actuating rod passesinto the conduit. Leakage through these two relatively moving surfacesis therefore confined to a small space surrounding the actuating rod andthe fluid is thereby prevented from coming into contact with thehydraulic fluid in the cylinder. The actuating of the mechanism expandsand compresses the bellows and the sealing effect is therebycontinuously maintained.

As has been noted above, the performance features of a device of thistype, valuable though they may be, must be coupled with a type o'fstructure occupying a relatively small space and' Il O be relativelyinexpensive to manufacture. Since these devices are conventionally usedin large numbers, the cost of an entire installation would be influencedvery greatly by small differences in cost of the individual valveassemblies. The preferred form of the present invention involves asubstantially coaxial arrangement in which a single rod forms the pistonrod, the valve actuator, and the means for cooperating with the holdingmechanism. The closing spring surrounds a portion of this rod and isconveniently confined within a chamber which is also coaxial with therod and the main hydraulic piston and cylinder. The pump of thepreferred form of the invention (the screw) is disposed so that thelower portion of the screw is opposite the portion of the` cylinderwhere the pressure is to be admitted. The opposite end of the screw ispreferably arranged at the upper end of the cylinder and corresponds tothe low pressure or reservoir side of the system.V A direct drivearrangement associates the screw with a relatively high speed motor, andthe opposite end of the motor may be devoted to the usual controlconnection and connecting point for the power leads. The hold.- ingmechanism and the motor control switch are preferably at the end of thedevice opposite from the valve itself. It will be seen that thisarrangement places the motor control switch and solenoid at a veryconvenient relationship with respect to the holding plate and that allof the parts are spaced in the best possible relationship one with theother requiring the minimum amount of wiring, conduits, and mechanicalconnections.

In any hydraulic mechanism, it is very desirable to provide anarrangement for assuring that the filling of the device to the requiredlevel with the fluid medium may be .accomplished without the requirementof a variety of complicated maneuvers. The problem, of course, is theremoval of accumulations of air which would prevent the complete fillingwith fluid as required. The filling of a device built according to thepresent invention is vastly simplified by the use of a hollow rod as anactuating member, since this rod preferably passes through the entirelength of the machine and is available at the upper or at the oppositeend from the controlled conduit. A lateral connection to the hollowinterior of this rod at the pressure side of the piston is provided, andthis permits the filling of the device on the lower pressure side of thepiston so that the fluid passes from that area around through the screwand into the pressure side without being inhibited by the generation ofair pressure. As the filling proceeds to a point where all of the air isremoved from the system, a cap is placed upon the upper end of thehollow actuating rod and the system is then in condition to develop thepressure required` under its normal operation. Y

The various features of the present invention will be analyzed in detailby a discussion of the particular embodiments which are illustrated inthe accompanying drawings. In these drawings: Y

Figure l is an elevation in section of the valve mechanism embodying thepresent invention with the valve in the closed position. y

Figure 2 is also an elevation in` section of the same mechanism shown inFigure 1 with the valve in the open position.

.Force-applying mechanism the valve actuator generally designated as Iis shown attached to the valve II by means of the connector I2. Thevalve II is associated with a conduit by threaded engagement at the openends. The active portion of the valve II comprises the moving valvemember I3 which cooperates with the seat indicated at I4. The valvemember I3 is rmly attached to the actuating or force-applying rod I5.Rod I5 enters the cylinder chamber I5 by a suitable opening I1 in theend-plate I8 as shown. It will be obvious that sliding engagement.occurs between the endplate I8 and the rod I5. The piston I9 is firmlyattached to the rod I5, and the rod continues on beyond the piston toform an extension 2l! surrounded by the chamber 2I and the spring 22.Spring 22 in the preferred form of the invention illustrated is of thecompression type and operates between the piston I9 and the spring seat23 to continuously urge the rod I5 and the valve member I3 toward theclosed position shown in Figure 1.

Disposed to one side of the cylinder I6, a cylindrical chamber 24 isprovided which communicates withvthe cylinder I6 by means of the ports25 and 2'6. The chamber 24 fits rather closely but with runningclearance around the threaded member 21 provided with the driving shaft28. This shaft is held in a suitable bearing 29 and is operativelyconnected with the motor 39. The opposite end of the armature of themotor 30 is Supported in the bearing system indicated at 3I. Motor 30 isadapted to drive the threaded member 21 at a relatively high speed, andthe interaction between the wall of the chamber 24 and the f3 threadedmember 21 is such that the hydraulic uid is forced in the direction ofthe port 26. The walls of the Chamber 24 have a tendency to retard therotational iiow of the uid to a velocity slower than the periphery ofthe rotating threaded member. With the speed differential thus created,the rotating threaded member tends to force the fluid in an axialdirection depending upon the direction of rotation and the direction ofthe particular helix angle used. The helix angle and direction ofrotation are selected in the present device so that pressure isgenerated at the port 26.

As soon as the rotation of the helical member 21 ceases, or slows to apoint where the pressure generated becomes less than sufficient toovercome the action of the spring 22, the annular passage provided bythe threads of the member 21 operates as a by-pass for the fluid whichthen flows in an opposite direction from port 25 through the threadedmember and out port 25 permitting the piston I9 to be moved in adownward direction by the spring 22.

In the preferred form of the present invention, the rod I5 is providedwith the hollow interior 32. After the assembly of the piston I 9 to therod I5, the vent passage 33 is machined as shown permittingcommunication between the cylinder II and the hollow interior 32. To llthe device with hydraulic uid, the plug 34 may be removed and fluidpumped into the upper portion 35 of the cylinder I6. This fluid fillsthe entire cylinder I6 by flowing through the port 25, the chamber 24,the port 26, and the lower portion of the cylinder I6. During this flowof fluid, air is constantly passing out through the passage 33 andthrough the hollow interior 32. The filling process is continued, ifdesired, until the liquid emerges from the upper end of the rod I5. Atthis point the cap 36 is placed in position, the

6 plug 34 inserted, and the device is then ready for operation as far asthe hydraulic system is concerned.

It will be obvious that there are other methods of applying fluidpressure to the port 26. The pump system may be of any variety, and ableed or by-pass may be provided as a separate conduit. If the conduitbe of extremely small dimensions, it is possible that the conduit may beleft open during the operation of the pump and the flow of the pumpwould be sucient to maintain pressure in the cylinder I6 regardless ofthe small amount passing through the by-pass conduit. If a more rapiddownward movement of the piston I9 were desired, the by-pass could bemade of larger diameter and provided with a valve which would remain ina closed position except when the motor 30 and the threaded member 21were not operating.

Holding mechanism Means are provided by the present invention to securethe valve in the opened position. In the preferred form, this mechanismhas the function of holding the valve open only so long as energy isbeing received from an outside source. The upper end of the rod I5 isprovided with the sliding member 31. This member is formed with theannular groove 38 for cooperation with the end 39 of the holding member40. The holding lever 49 is pivoted at 4I, and the radial distance fromthe axis of the pivot 4I to the end 39, and the distance from the axisof the pivot 4I to the side of the sliding member 31 is such that theholding lever 49 is maintained in an elevated position as shown untilthe annular groove 33 moves upwardly in amount suiiicient to provideclearance to the end 39. As the sliding member 31 moves upwardly withthe rod I5 after that point is reached, the holding lever 40 rotates ina clockwise direction as shown in Figures 1 and 2 and assumes agenerally horizontal position at which time the end 39 projects into theannular groove recess 38. As long as the holding lever 49 is maintainedin a generally horizontal position, it will be obvious that downwardmovement of the rod I5 and the sliding member 31 are prevented.

The holding of the lever 49 in horizontal position is accomplished bythe solenoid generally indicated at 42. Lever 49 is constructed ofmagnetic material; and as long as energy is supplied to the solenoid 42,the attraction is suflicient to maintain the holding lever 4U in ahorizontal position against the torque provided by the spring forceapplied at the end 39 kby the groove 38. As soon as the energy supply tothe solenoid 42 is terminated, the holding member 4D is no longerbalanced or held in horizontal position, and the rotation to theposition shown in Figure 1 takes place.

The operation of the holding lever 49 and the running-of the motor 39are associated through the switch 98. The switch 48 is provided with theactuating button 49, and the holding member 40 is tted with theprojection or actuating surface 50. When the holding leverY 40approaches the horizontal position, the actuating surface 59 cooperateswith the button 49 causing switch 48 to interrupt the current to themotor 30. After this has been accomplished, the supply of electricalenergy to the device is entirely devoted to maintaining the magneticfield of the solenoid 42. 'I'he running of motor 39 requires twoconditions to be present: (a)

7 the; receipt of energy through the lead 511, and (ab) theposition ofthe holding member at a point such that the actuating surface 50 clearsthe button 49. Electrical energy isv supplied to the solenoid 42, theswitch 48, and the motor 30 by means of suitable leads 52, 53, and 54.

Sealing It will be obvious that the conduit with which the valve H1 isassociated will supply fluid which will have a tendency to occupy theentire space iny and around the valve mechanism includingthat ,portionsabove the moving valve member I3. The iiuid in this area will have atendency to work its way through the opening Il around the rod I.5 andinto the confines of the cylinder I6 if it were not for the presence ofthe bellows member 55. The bellows member is securely attached to thelower portion of the piston and also to a member iixed with respect tothe end plate i8. Movement of the piston causes a tendency for thebellows member 55 to axially expand and contract while still maintainingthe uid` contained inside it isolated from that of the cylinder I6. Toprotect the bellows member 55, the tube 56 is provided which looselysurrounds the bellows and operates as a combined sheath and guidingmember.

The particular embodiments of the present invention which have beenillustrated in the accompanying drawings and discussed herein are forillustrative purposes only and are not to be considered as limiting thescopeof the appended claims.

I claim:

f l. Actuating mechanism comprising a forceapplying rod; piston meansoperatively connected to said force-applying rod to drive the same;cylinder means cooperating with said piston means; huid-pressuregenerating means communicating with said cylinder means; and retain.-ing means cooperating with said force-applying rod to hold the same in aposition established by said piston means, said retaining meansincluding a sliding member fixed with respect to said rod and having arecess, a holding lever pivotally mounted for rotation in a planesubstantially parallel to said rod on an axis disposed to one side onsaid sliding member and having an engaging projection extending fromsaid axis into the path of travel of said recess and formed to withdrawtherefrom on rotation about said axis, and electromagnetic meansdisposed to secure said holding member against the forces applied onsaid projection.

2. A valve-actuating mechanism comprising: a force-applying rod; biasingmeans disposed to urge said rod in a particular direction; piston meansoperatively connected to said force-applying rod to drive the same;cylinder means cooperating with said piston means; fluid-pressuregenerating means communicating with said cylinder means, said pressuregenerating means. providing an exhaust for said fluid from said cylindermeansv on termination of pressure generation; and retaining meanscooperating with said force-applying rod to hold the same in a positionestablished by said biasing means and piston means, said retaining meansincluding a sliding member xed with respect to said rod and having arecess, a.L

holding lever pivotally mounted for rotation in a plane substantiallyparallel to said rod on an; axis disposed to one side of said slidingmembei and having an engaging projection extending from said axis intothe path of travel of said recess and formed to withdraw therefrom onrotation about said axis, and electromagnetic means disposed to securesaid holding member against the forces applied on said projection.

3. Actuating mechanism, comprising: forceapplying means; power-drivenforce-generating means operatively connected to position saidforce-applying means; latch means including detent means mounted formovement to and from a position engaging said force-applying means tolock the same in position, and also including power-operated biasingmeans urging said detent means to locking position; and iixed biasingmeans urging said detent means from engaging position, said xed biasingmeans having less force than said power-operated biasing means.

4. A valve-actuating mechanism, comprising: force-applying means;power-driven force-generating means oppositely connected to positionsaid force-applying means; biasing means opposing said force-genertaingmeans;` latch means including detent means mounted for movement to andfrom a position engaging said force-applying means to lock the same inposition, and also including power-operated biasing means urging saiddetent means to locking position; and fixedv biasing means urging saiddetent means from engaging position, said fixed biasing means havingless force than said power-operated biasing means.

NORTON E. HEINTZELMAN.

References Cited in the ille of this patent UNITED STATES PATENTS NumberName Date 491,369 Moyer et al. Feb. 7, 1893 679,898v Josse Aug. 6, 1901,

1,836,813 Rankin Dec. 15, 1931 2,020,618 Persons Nov. 12, 1935 2,081,055Kiracofe May 18, 1937 2,127,961 Ray Aug. 23, 1938. 2,276,591 Ray Mar.17. 1942 2,277,836A Arnold Mar. 3l, 1942 2,439,523 Miller etal. Apr.131948.

